Numerous padlock constructions have been developed and are widely employed by individuals to prevent unauthorized persons from gaining access to any particular item or area which has been closed and locked. In this regard, many lock constructions are designed to be opened by a key, while numerous combination lock constructions have also been developed which are open by knowledge of a particular combination.
One particular type of combination lock that has become very popular due to its convenience of use is a combination lock which employs a plurality of rotatable independent dials, each of which forms one of the indicia, usually numerals or letters, which comprise a combination for releasing the lock. Typically, the combination lock has one mode or position in which the user is able to set or reset the desired combination sequence. However, in spite of the popularity of these combination locks, key-operated locks remain the most popular and most prevalent.
In spite of the substantial effort which has been expended in developing key control padlocks, prior art constructions continue to suffer from the use of components which are difficult and expensive to manufacture. In particular, one of the principal components of key controlled padlocks is the rotatable cylinder plug which is rotationally mounted in a cylinder housing and is constructed for being responsive to a particularly key for enabling the cylinder plug to rotate about its central axis.
Although the cylinder plug is a principal element and is required in each key controlled padlock construction, cylinder plugs are expensive to manufacture since they must be individually cut from round metal rods and then individually machined to obtain the desired construction. As a result, substantial effort and expense is required. Furthermore, although this problem has existed in the art for numerous years, no effective resolution of this difficulty has been realized.
Another common problem which has consistently plagued prior art constructions is the assembly and production costs associated with key controlled padlocks. In order to attain a padlock which provides all of the features desired by consumers, prior art constructions typically incorporate numerous small components, each of which require expensive assembly procedures to produce the final product. As a result, these prior art lock constructions are expensive to produce, thereby reducing the ability of these locks to reach a broad base of consumers.
Another problem commonly found with prior art padlocks is the inability of these prior art constructions to prevent contaminants from reaching the rotatable, internal components of the lock, thereby causing damage to these components or interfering with the ease of operation of the lock. Although numerous attempts have been made to reduce the adverse effects caused by contaminants reaching these components, such attempts have been incapable of completely eliminating this problem.
A further difficulty which has recently arisen and has caused consumers to become increasingly concerned is the requirement that all secured locks may be broken by customs officers and/or inspection or security personnel in order to gain access to luggage which is deemed suspicious. Under security regulations that have recently been implemented, all luggage must be scanned or inspected to prevent the transportation of potentially dangerous items or products which are deemed to be undesirable. In those instances when the luggage is scanned and further visual inspection is required, the inspectors have the authority to open the luggage for visual inspection, including physically breaking any lock which may be on the luggage and cannot be opened by the customs officers.
Consequently with these new regulations presently being implemented, all prior art lock systems which are incapable of being opened by inspectors and/or security personnel are subject to being physically broken, in order to gain access to any luggage which needs to be visually inspected. As a result, consumers will be faced with the possibility that any lock system employed to protect the contents of the suitcase can be physically removed by security personnel, leaving the luggage completely unprotected during the remainder of the trip.
Furthermore, even in those instances when security personnel are able to open a padlock in order to visually inspect the contents of the suitcase, the consumer is unable to know with certainty whether or not a particular locked suitcase had been visually inspected by the security personnel. Without any positive indication regarding the security personnel's activity with a particular piece of luggage, the consumer is unable to know whether any missing or damaged item in the suitcase may have resulted during a security inspection.
Therefore, it is a principal object of the present invention to provide a padlock which can be opened by employing either a user key or a master key and incorporates an automatically initiated positive indicator or signal for informing the consumer whenever the padlock has been opened using the master key.
Another object of the present invention is to provide a padlock having the characteristic features described above which is easily produced and provides the user with complete control over re-setting of the indicator.
Another object of the present invention is to provide a padlock having the characteristic features described above which automatically locks the indicator/signal in its raised position once the indicator/signal has been activated.
Another object of the present invention is to provide a padlock having the characteristic features described above which also provides an indicator or signal which is highly visible and easily seen by the user.
A further object of the present invention is to provide a padlock having the characteristic features described above which requires a separate key for resetting the indicator or signal for enabling only the user to reset the indicator or signal when the lock has been opened.
Other and more specific objects will in part be obvious and will in part appear hereinafter.